(a) Field of the Invention
The present invention relates to a multilayer composite being suitable for the production of packaging materials, particularly containers, and to an easily openable container produced by using the multilayer composite, which excels both in hermetic sealability and in openability and, therefore, is suitable particularly for packaging foods, medicines, and cosmetics.
(b) Description of the Related Art
Polystyrene hermetically sealed containers have mainly been used for packaging dessert foods or dairy products.
Polystyrene hermetically sealed containers, however, have a problem that the hermetic sealability thereof cannot be improved without decreasing openability. In order to solve the problem, aluminum foil or plastics film coated with hot melt adhesives or lacquer adhesives has generally been used as a lid member to improve openability. Nonetheless, such a kind of hermetically sealed containers are still insufficient in openability, and most of those are difficult for infants and young boys and girls to open. There are further problems including a poor oil resistance and an increase in cost. In particular, hermetically sealed containers for packaging bean curd, which are produced by heat sealing polystyrene containers with lids of CPP film, are so difficult to open that housewives are obliged to cut the lids of CPP film by using a kitchen knife to take out the bean curd.
Since all these containers have a defect in openability, and using lids with specified sealant to improve openability also results in a problem of increasing the cost, the development of containers having both good hermetic sealability and easy openability has been hoped for.